I’ve ground my molars while stuck behind someone wearing lace-up boots, and that’s before the new, anatomically correct scanner, which takes a graphic picture of your bits, paunches and other concessions to gravity.

It’s a whopping assault on our dignity. The airlines would love to return to the days of putting the customer first. To the guy in uniform with blue rubber gloves, we’re potential terrorists with explosives in our undergarments just pretending to be going home to grandma’s house for the holidays.

Try feeling the Transportation Safety Administration agent’s pain. Exposed to public scrutiny while they work, it’s easy to get annoyed when TSA workers chit-chat about last night’s game or today’s lunch. Still, the mistakes are whoppers: A man whose urostomy bag was broken, a breast-cancer survivor compelled to show her prosthesis.

Enduring security screening is all we are asked to do in the war on terror while others are subjected to multiple deployments to Iraq and Afghanistan.

It should be embarrassing to shirk our part in averting another attack. Yet for a loud minority being touched by a TSA agent is too much of an inconvenience.

Enter John Tyner, a guy with a cell-phone camera who decided against the full-body image in favor of the pat-down, achieving instant celebrity when he warned the agent “Touch my junk and I’ll have you arrested.”

To him, let me say, in another cliche of the moment, Man up! For a country where porn gets the most Internet traffic and the TV family hour is awash in sex, it’s interesting that the place where we’ve decided to get prudish is an antiseptic exercise where the purpose is to keep a 747 with 500 people on board from being blown up.

Although Tyner and his fellow travelers make up a tiny segment of Americans, it’s a loud segment ready for a close-up - - just not in front of a scanner. Local news crews race to the nearest airport to record every complaint. Talk-show hosts can’t book the whiners fast enough.

TSA head John Pistole had to do a lot of damage control last week. In the media whirl, he seemed to say he was going to reconsider the measures before saying that he couldn’t because, of course, he can’t. He has a country to keep safe, even in the face of threats of an opt-out protest by passengers today that might snarl air travel on the busiest day of the year.

Like so much else, this problem is all the fault of Barack Obama’s socialistic Big Brother state when, in fact, the apparatus was built by President George W. Bush.

After the World Trade Center fell, Bush - who ignored the warning that Osama bin Laden wanted to attack within the U.S. and likely by plane - decided he had to do something fast. The last line of defense when all else fails, as it did on 9/11, was beefing up airport security.

There wasn’t time to build it smart, but there was money to build it big. Republicans, even small government ones, ridiculed anyone who piped up about the wisdom of creating a gigantic bureaucracy or worried about privacy rights.

Security is always reactive. After Richard Reid, a/k/a the shoe bomber, we had to take off our shoes. Another attack led to a ban on bottles of shampoo and water. After the Yemeni bombs, out went printer cartridges in luggage. After the underwear bomber, the revealing full-body scanner.

Israel would be a good model if we wanted to openly profile and risk getting a bad name. But what if our enemies profile themselves? We know who hates us and is intent on our annihilation. We also know the weapon of choice is an airplane.

Is there a way - short of profiling - to concentrate on the 20-year-old from Yemen and go easy on the man from Kansas with the artificial hip? The fear is our methods will be sussed out by our enemies. Go easy on a nun and terrorists will soon be dressing as Carmelites. Exempt grandmothers and only grandmothers will be recruited to carry explosives.

There will come a limit, as machines threaten to eat our airports. The head of security at Amsterdam Airport Schiphol said last week she doesn’t have another inch of space for equipment. When security pushes out Cinnabon, the terrorists really will have won.

It’s a terrible, undignified, frustrating, wasteful system until you imagine a world in which check-in security nabbed the 9/11 terrorists contemplating their vestal virgins. We wouldn’t have lost 3,000 souls that day, nor be fighting two wars a decade later.

So this holiday, let’s honor our pact as citizens of Airport U.S.A. I go through security and so do you. You don’t get to opt-out because we are all in this together. When the seat-belt sign goes off, pull down your tray table, release your seat from the full and upright position and drink to the friendly skies.

[Margaret Carlson, author of “Anyone Can Grow Up: How George Bush and I Made It to the White House” and former White House correspondent for Time magazine, is a Bloomberg News columnist.]